1. Field of the Invention
This invention relates to water-based functional fluids thickened by an associative polyether thickener whose thickening power is enhanced by the addition of certain fatty acid amides.
2. Description of the Prior Art
U.S. Pat. No. 4,411,819 discloses the advantages of using associative polyether thickeners to thicken water-based functional fluids. Although these thickeners have excellent thickening ability, they are expensive and new methods for decreasing the amount of such thickeners have been explored. For instance, U.S. Pat. No. 4,312,775 discloses that reduced amounts of associative polyether thickener can be used in conjunction with ethoxylated phosphate ester.